DUI Blood Tests & DNA

By
Law Offices of Virginia L. Landry, Inc.
|August 30, 2017

Say you were arrested for driving under the influence (DUI) and you strongly
believe that the blood sample came back with too high of a blood alcohol
concentration (BAC). Now, you want to see if you can have a DNA test of
the blood sample to make sure it was yours.

You want to know, “Could my blood sample have been switched at the
lab?” You never heard of this defense before, but you know there
are labs that do paternity and immigration DNA testing. Maybe you even
went so far as to purchase a breathalyzer and ran your own tests, which
involved drinking the same amount and type of alcohol over the same time
period, and your results came back with a much lower BAC. Sounds extreme,
but people have conducted their own tests of this sort before.

Getting the Blood Re-Tested

Determining your BAC level based on a drinking pattern can be very difficult,
especially for the layperson. While experts can disagree on a person’s
BAC at the time they were driving, blood results tend to be accurate, though
not infallible. Conversely, breath samples have more room for error due
to factors, such as body weight, gender, medical conditions (e.g. diabetes),
use of mouthwash, time since last drink, etc.

Most of the independent labs used by
DUI attorneys test for BAC level and the basic blood type. There certainly
have been cases in the past where fermentation led to a false reading;
false readings can arise when the blood has been left in ambient temperature
for too long. Blood samples can even coagulate when they have been compromised.
Getting a blood split to independently retest your blood sample can be
a problem if your attorney isn’t familiar with the process.

Can I Get a DNA Test?

But what about DNA testing? DNA tests can be costly; the best thing to
do is consider getting a blood split, meaning get the blood sample retested.
If you are still dissatisfied with the results, you can discuss the pros
and cons of getting a DNA test with your
DUI defense attorney.

The information on this website is for general information purposes only.
Nothing on this site should be taken as legal advice for any individual
case or situation. This information is not intended to create, and receipt
or viewing does not constitute, an attorney-client relationship.